1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Lunna [17]
4 years ago
15

A rock rolls down a steep hill. it's initial velocity is 1 meter per second. by the time it reaches the bottom of the hill 30 se

conds later, it's velocity is 7 meters per second. what is the acceleration of the rock?
Physics
2 answers:
Vlada [557]4 years ago
5 0
By applying
a=v-u/t
a=1-7/30
a=-6/30
a=-0.2ms^-2
worty [1.4K]4 years ago
4 0

Answer:

0.2m/s²

Explanation:

Acceleration is defined as the change in velocity of a body with respect to time. Mathematically,

Acceleration = change in velocity/time

Change in velocity = Final velocity - initial velocity

Acceleration = final velocity - initial velocity/time

Given initial velocity = 1m/s

Final velocity = 7m/s

Time taken = 30seconds

Substituting this values into acceleration formula we will have;

Acceleration = 7-1/30

Acceleration = 6/30

Acceleration = 0.2m/s²

Therefore the acceleration of the rock is 0.2m/s²

You might be interested in
How much energy is stored in a 2.80-cm-diameter, 14.0-cm-long solenoid that has 200 turns of wire and carries a current of 0.800
ozzi

Answer:

The energy stored in the solenoid is 7.078 x 10⁻⁵ J

Explanation:

Given;

diameter of the solenoid, d = 2.80 cm

radius of the solenoid, r = d/2 = 1.4 cm

length of the solenoid, L = 14 cm = 0.14 m

number of turns, N = 200 turns

current in the solenoid, I = 0.8 A

The cross sectional area of the solenoid is given as;

A = \pi r^2\\\\A = \pi (0.014)^2\\\\A = 6.16*10^{-4} \ m^2

The inductance of the solenoid is given by;

L = \frac{\mu_0 N^2A}{l} \\\\L =  \frac{(4\pi*10^{-7})(200^2)(6.16*10^{-4})}{0.14}\\\\L = 2.212*10^{-4} \ H

The energy stored in the solenoid is given by;

E = ¹/₂LI²

E = ¹/₂(2.212 x 10⁻⁴)(0.8)²

E = 7.078 x 10⁻⁵ J

Therefore, the energy stored in the solenoid is 7.078 x 10⁻⁵ J

8 0
3 years ago
A car travels at a steady 40.0 m/s around a horizontal curve of radius 200 m. What is the minimumcoefficient of static friction
zhenek [66]

Answer:

c. 0.816

Explanation:

Let the mass of car be 'm' and coefficient of static friction be 'μ'.

Given:

Speed of the car (v) = 40.0 m/s

Radius of the curve (R) = 200 m

As the car is making a circular turn, the force acting on it is centripetal force which is given as:

Centripetal force is, F_c=\frac{mv^2}{R}

The frictional force is given as:

Friction = Normal force × Coefficient of static friction

f=\mu N

As there is no vertical motion, therefore, N=mg. So,

f=\mu mg

Now, the centripetal force is provided by the frictional force. Therefore,

Frictional force = Centripetal force

f=F_c\\\\\mu mg=\frac{mv^2}{R}\\\\\mu=\frac{v^2}{Rg}

Plug in the given values and solve for 'μ'. This gives,

\mu = \frac{(40\ m/s)^2}{200\ m\times 9.8\ m/s^2}\\\\\mu=\frac{1600\ m^2/s^2}{1960\ m^2/s^2}\\\\\mu=0.816

Therefore, option (c) is correct.

7 0
4 years ago
The variable that you change during an experiment is called what type of variable?
elena-s [515]
The independent variable 
7 0
3 years ago
Read 2 more answers
A stone has a volume of 0.50 cm³ and a mass of
Dafna1 [17]

Answer:

ρ = M / V = 2 g / .5 cm^3 = 4 g/cm^3

8 0
2 years ago
A man lifts a 120 kg barbell 2 m above the ground . What is the gain in gravitational PE of the barbell?
SpyIntel [72]

Answer:

2,352 Joules

Explanation:

At the ground, the barbell has a classical mechanical energy value of zero. There is no classical kinetic or potential energy for the barbell. The moment the man starts to lift the barbell, he does work on the barbell and transfers kinetic energy to it due to the motion. At its maximum height where the man lifts the barbell to a stop, the kinetic energy is zero because it transformed into gravitational potential energy stored in the gravitational field. Our reference point for potential was defined to be zero at the floor, therefore we can say that the gravitational potential energy at 2 meters is:

U=mgh=(120kg)(9.8m/s^2)(2m)=2,352J

7 0
3 years ago
Other questions:
  • A battery charges capacitor A until the potential difference between the two conductors of the capacitor is V.
    9·2 answers
  • If an object has a kinetic energy of 30 j and mass of 34kg how fast is the object moving ?
    8·1 answer
  • A person is using a rope to lower a 5.0-n bucket into a well with a constant speed of 2.0 m/s. What is the magnitude of the forc
    6·2 answers
  • A wind turbine takes in energy from wind with the goal of converting it into electrical energy. Much of the wind energy is also
    10·2 answers
  • According to the octet rule, an atom with two electron shells is most stable when it contains eight
    8·1 answer
  • A 20.0 μf capacitor is charged to a potential difference of 850 v. the terminals of the charged capacitor are then connected to
    14·1 answer
  • Which of the following is the correct SI unit to use in measuring the mass of a boulder
    5·2 answers
  • An energy-efficient water heater draws 4 amps in a 220-volt circuit. It costs $75 more that a standard water heater that draws 1
    13·1 answer
  • What is the average velocity of Runner C for the first 15 seconds? Question 5 options: 1.3 m/s -2.7 m/s -1.3 m/s 2.7 m/s
    15·2 answers
  • If you jog for 1 hr and travel 10 km, the calculation of 10 km/hr describes your.
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!