Answer: The force needed is 140.22 Newtons.
Explanation:
The key assumption in this problem is that the acceleration is constant along the path of the barrel bringing the pellet from velocity 0 to 155 m/s. This means the velocity is linearly increasing in time.
The force exerted on the pellet is
F = m a
In order to calculate the acceleration, given the displacement d,
we will need to determine the time t it took for the pellet to make the distance through the barrel of 0.6m. That time can be determined using the average velocity of the pellet while traveling through the barrel. Since the velocity is a linear function of time, as mentioned above, the average is easy to calculate as:
This value can be used to determine the time for the pellet through the barrel:
Finally, we can use the above to calculate the force:
The roughness of the surface, the mass of the object, and the area of contact.
Answer:
a)188.65m
b)154.35m
c)243.7m
Explanation:
Given data:
(a) The distance from the kicker to each of the 2 spectators is given by:
where,
v= speed of sound
=time taken for the sound waves to reach the ears
m
(b)
where,
v= speed of sound
=time taken for the sound waves to reach the ears
(c)As the angle b/w slight lines from the two spectators to the player is right angle,
hypotenuse=the distance b/w 2 spectators
and, the slight lines are the other 2 lines
You should draw a free body diagram, or a diagram of sorts. It’s always helpful to do so when solving physics questions.
Answer:
57 kg
Explanation:
Mass of seesaw = 20 kg
Length of seesaw = 4 m
Mass of child on the longer end = 30 kg
The weight of the seesaw acts at the center i.e. 2m
The algebraic sum of moments of all forces about any point is zero, hence, using the fulcrum as the reference point:
[x * 9.8* 1.5] - [20 * 9.8* (2.5 - 2)] - [30 * 9.8 * 2.5] = 0
=> 14.7x = (20*9.8*0.5) + 735
14.7x = 98 + 735
14.7x = 833
=> x = 833/14.7
x = 57 kg