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2 years ago

7

What is the answer to this question?

1 answer:

icang [17]2 years ago

8 0

Answer:

Explanation:

In a velocity/time (aka acceleration) graph, the slope of a line indicates the value of the acceleration in m/s/s. Acceleration is the change in velocity over the change in time. From 0 - 2 seconds, there is no change in velocity, so the acceleration during this interval is 0 (which is the same as the slope of the line). From 2 - 4 seconds, the slope of the line is -2, so the acceleration during the time interval from 2 to 4 seconds is -2 (negative because David is slowing down but is still going the same direction: to the right).

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What is the velocity of a car that travels -50 meters in 5 seconds then 10 meters in 5 seconds

diamong [38]

Answer:

2 m/s

Explanation:

The first part of the question the car is going in reverse or negative along the x axis. Then the second part the car is moving forward along the x axis. So the car would only have velocity in the current direction of movement. So our equation for velocity is as follows.

v = d/t

v = 10 m/5 s

v = 2 m/s

3 0

2 years ago

What is the density of a cube that has a mass of 3.75 g and a volume of 3 mL?

valina [46]

Answer:

$\displaystyle \rho=1.25\ g/ml$

Explanation:

<u>Density </u>

The density of a substance is the mass per unit volume. The density varies with temperature and pressure.

The formula to calculate the density of a substance of mass (m) and volume (V) is:

$\displaystyle \rho=\frac{m}{V}$

The cube has a mass of m=3.75 g and a volume of V=3 ml, thus the density is:

$\displaystyle \rho=\frac{3.75\ g}{3\ ml}$

$\boxed{\displaystyle \rho=1.25\ g/ml}$

Since 1 kg=1000 mg and 1 lt = 1000 ml, the density has the same value but with different units:

$\displaystyle \rho=1.25\ kg/l$

6 0

2 years ago

A hailstone traveling with a velocity of 43 meters/second comes to a virtual stop 0.28 seconds after hitting water. What is the

shutvik [7]

Acceleration=(change in speed)/(time for the change). 43/0.28 = 153.6 m/s^2.

6 0

2 years ago

Read 2 more answers

A ball rolls down a ramp. A small amount of friction heats up the ball. What energy transformations are taking place?

Natasha2012 [34]

Answer:kinetic energy converted to heat energy

Explanation:

As the ball rolls down kinetic energy is converted to heat energy

6 0

3 years ago

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A hoop (I = MR2) of mass 3 kg and radius 1.1 m is rolling at a center-of-mass speed of 11 m/s. An external force does 842 J of w

Scilla [17]

Answer:

$v_f = 20 m/s$

Explanation:

Since the hoop is rolling on the floor so its total kinetic energy is given as

$KE = \frac{1}{2}mv^2 + \frac{1}{2} I\omega^2$

now for pure rolling condition we will have

$v = R\omega$

also we have

$I = mR^2$

now we will have

$KE = \frac{1}{2}mv^2 + \frac{1}{2}(mR^2)\frac{v^2}{R^2}$

$KE = mv^2$

now by work energy theorem we can say

$W = KE_f - KE_i$

$842 J = mv_f^2 - mv_i^2$

$842 = 3(v_f^2) - 3\times 11^2$

now solve for final speed

$v_f = 20 m/s$

3 0

2 years ago