Answer:
C)
Explanation: In freefall motion object always has gravity as its acceleration.
Answer:
There are a number of models as explained below.
Explanation:
- Depending on the position of the earth in the orbit, stars will be in different positions relative to the distant stars.
This model can be explained by the parallax effect. An object is viewed differently by the left and the right eye.
Reference can be made to the geocentric and heliocentric arguments. The first view argues that heavens are composed of 55 concentric spheres.
On the other hand, the heliocentric system, proposed by Copernicus, suggested that the Sun, not the earth, was the center of the solar system.
Answer:
374 N
Explanation:
N = normal force acting on the skier
m = mass of the skier = 82.5
From the force diagram, force equation perpendicular to the slope is given as
N = mg Cos18.7
μ = Coefficient of friction = 0.150
frictional force is given as
f = μN
f = μmg Cos18.7
F = force applied by the rope
Force equation parallel to the slope is given as
F - f - mg Sin18.7 = 0
F - μmg Cos18.7 - mg Sin18.7 = 0
F = μmg Cos18.7 + mg Sin18.7
F = (0.150 x 82.5 x 9.8) Cos18.7 + (82.5 x 9.8) Sin18.7
F = 374 N
To solve this problem we will apply the linear motion kinematic equations, specifically the concept of acceleration as a function of speed and time, as well as Newton's second law.
PART A) Acceleration can be described as changing the speed in a period of time therefore,
Force is the proportional change between mass and acceleration therefore
PART B) We will apply the same concept given but now we will change the time to 21s therefore:
Now the force
Answer:
53.33 seconds
Explanation:
From the question;
- Power of the motor is 75 kW or 75000 W
- Depth or height is 150 m
- Volume of water is 400 m³
We are required to determine taken to raise the water from the given height.
We know that density of water is 1000 kg/m³
Therefore;
Mass of water = 400 m³ × 1000 kg/m³
= 4.0 × 10^5 kg
Thus, force required to raise the water;
= 4.0 × 10^5 kg × 10 N/kg
= 4.0 × 10^6 N
To determine the time;
we use the formula;
Time = work done ÷ power
= (4.0 × 10^6 N × 150 m) ÷ 75000 Joules/s
= 53.33 seconds
Therefore, time taken to raise the water is 53.33 seconds
