Answer:
Explanation:
Since energy is conserved:
2
mu
2
=
2
mv
2
+mgh
⇒u
2
=v
2
+2gh
⇒(3)
2
=v
2
+2(9.8)(0.5−0.5cos60)
⇒v=2m/s
Answer:
0.53 m
Explanation:
First of all, we have to consider the vertical motion of the ball, in order to find the time it takes for the marble to reach the ground. The initial height is
, the initial vertical velocity is zero, while the acceleration is
, so the vertical position at time t is given by

By demanding y(t)=0, we find the time t at which the ball reaches the ground:


Now we can find the horizontal range of the marble: we know the initial horizontal speed (v=1.24 m/s), we know the total time of the motion (t=0.43 s), and since the horizontal speed is constant, the total distance traveled on the horizontal direction is

Answer:
3.5 seconds of flight time; 13.9 m from the base of the cliff
Explanation:
Answer:
D. The cart is moving at a constant speed or velocity
Explanation:
Equilibrium is a state of body in which it is either at rest or moves with uniform velocity. The sum of forces acting on such a body is always zero and the sum of all the torques acting on it is also zero.
There are two types of equilibrium as follows:
Static Equilibrium: When a body is at rest it is said to be in static equilibrium.
Dynamic Equilibrium: When a body is moving with constant velocity, then it is said to be in dynamic equilibrium.
Hence, the correct option here will be:
<u>D. The cart is moving at a constant speed or velocity</u>
Answer:
6370 J
Explanation:
By the law of energy conservation, the work done by the student would be the change in potential enegy from 1st floor to 3rd floor, or a change of 13 m

where m = 50kg is the mass of the student, g = 9.8 m/s2 is the gravitational constant and h = 13 m is the height difference
