The quantity that has a magnitude of zero when the ball is at the highest point in its trajectory is
the vertical velocity.
In fact, the motion of the ball consists of two separate motions:
- the horizontal motion, on the x-axis, which is a uniform motion with constant velocity
, where
- the vertical motion, on the y-axis, which is a uniformly accelerated motion with constant acceleration
directed downwards, and with initial velocity
. Due to the presence of the acceleration g on the vertical direction (pointing in the opposite direction of the initial vertical velocity), the vertical velocity of the ball decreases as it goes higher, up to a point where it becomes zero and it reverses its direction: when the vertical velocity becomes zero, the ball has reached its maximum height.
Answer:
25.82 m/s
Explanation:
We are given;
Force exerted by baseball player; F = 100 N
Distance covered by ball; d = 0.5 m
Mass of ball; m = 0.15 kg
Now, to get the velocity at which the ball leaves his hand, we will equate the work done to the kinetic energy.
We should note that work done is a measure of the energy exerted by the baseball player.
Thus;
F × d = ½mv²
100 × 0.5 = ½ × 0.15 × v²
v² = (2 × 100 × 0.5)/0.15
v² = 666.67
v = √666.67
v = 25.82 m/s
Answer:128 N
Explanation:
Sample of 3 cm and 4 mm diameter found to break under a minimum force of 128 N .
If sample is 1.5 cm long with same cross-sectional area then minimum force required to break is also 128 N because the applied force is same for any length and diameter of tendon.
There are huge losses in the transmission, production and usage of electricity and the reduction of these losses in order to save electricity is called as conservation of energy.
As per the statistics, there is loss of nearly 4% while the transmission of electricity. Like wise during production also, lot of electricity get wasted due to the inefficient material used. None of the production material nor the equipment used have 100% efficiency and thus there is always a possibility of energy wastage.
When it is said that the energy is wasted , it simply means that the energy production which should have been 100% as per calculation is not completely derived from the source due to the inefficient conversion process. For example, a turbine while rotating must convert 100 % of the water energy or water falling on it into electrical energy but the turbine is not able to do so as some of the water is lost or its energy is lost before conversion while going through the mechanical process.
Explanation:
Given that,
Force with which a child hits a ball is 350 N
Time of contact is 0.12 s
We need to find the impulse received by the ball. The impulse delivered is given by :
So, the impulse is 42 N-m..
We know that he change in momentum is also equal to the impulse delivered.
So, impulse = 42 N-m and change in momentum =42 N-m.
