Answer:
The acceleration of the sprinter is 1.4 m/s²
Explanation:
Hi there!
The equation of position of the sprinter is the following:
x = x0 + v0 · t + 1/2 · a · t²
Where:
x = position of the sprinter at a time t.
x0 = initial position.
v0 = initial velocity.
t = time.
a = acceleration.
Since the origin of the frame of reference is located at the starting point and the sprinter starts from rest, then, x0 and v0 are equal to zero:
x = 1/2 · a · t²
At t = 9.9 s, x = 71 m
71 m = 1/2 · a · (9.9 s)²
2 · 71 m / (9.9 s)² = a
a = 1.4 m/s²
The acceleration of the sprinter is 1.4 m/s²
An elevator has 750,000 J when it is lived 500 meters in the air
Answer: Option D
<u>Explanation:</u>
The expression to find the potential energy completely on the basis of forces that on two objects. It can be written as

Where,
m – mass of object
Acceleration due to gravity = 
h = 500 meters
Force = 1500 Newton
As we know, according to Newton second law of motion, the force can be expressed in terms of mass and gravity (F= ma). So, the potential energy can be calculated as

Hence, an elevator has 750,000 J when it is lived 500 meters in the air.
A. momentum = mass x velocity
b. kinetic energy = 1/2 x mass x velocity^2
Although total momentum is conserved, total kinetic energy is not necessarily equal. It’s because Jay acted a force on the skateboard and increased the energy of the system.
Answer:
Option D (N/A-m)(m)(m/s)
Explanation:
(N/A-m)(m)(m/s) is the required dimensional analysis for calculation of emi