Answer:
Mass of the box = 0.9433 kg
Explanation:
Mass of racket-ball
= 0.00427 kg
Velocity of racket-ball before collision
= 22.3 m/s
Velocity of racket-ball after collision with box
= -11.5 m/s
[Since ball is bouncing back, so velocity is taken negative.]
Velocity of the box before collision
= 0 m/s
<em>[Since the box is stationary, so velocity is taken zero]</em>
Velocity of box moving forward after collision
= 1.53 m/s
To find the mas of the box
.
By law of conservation of momentum we have:
Momentum before collision = Momentum after collision
This can be written as:


We can plugin the given value to find 


Adding both sides by 0.4911


Dividing both sides by 1.53.


∴
kg
Mass of the box = 0.9433 kg (Answer)
Answer:
P = 216 Watts
Explanation:
Given that,
Resistance 1, 
Resistance 2, 
Voltage, V = 36 V
We need to find the power dissipated by the 6 ohms resistor. In case of parallel circuit, voltage throughout the circuit is same while the current is different.
Firstly, lets find current of the 6 ohms resistor such that,
V = IR

The power dissipated by 6 ohms resistor is given by :


So, the power dissipated across 6 ohm resistor is 126 watts.
Find stress using the formula Stress = Force / Area. Here, force
exerted by 85kg person on stool is F = mg = 85kg * 9.8 m/s^2 = 833N. Find total
area of 3 legs A = 3 π (D/2)^2 = 3 π (2.5 x 10^-2 / 2)^2 = 1.4726 x 10^-3 m^2.
Now substitute in Stress = Force/Area. Stress = 833N / 1.4726 x 10^-3 m^2 =
5.656 x 10^5 N/m^2. Find strain using the formula strain = Stress / Young’s
modulus. For wood, Y = 1.3 x 10^10 N/m^2. Thus, strain = 5.656x10^5 N/m^2 /
1.3x10^10 N/m^2 = 4.35 x 10^-5 = 0.00435%.
Therefore, the legs decrease by 0.00435%
The Gravitationa potential energy of the mass (PEG) is given by:

where
m is the mass
g is the gravitational acceleration
h is the heigth of the mass above the reference level (the ground)
In this problem,

and

, therefore the gravitational potential energy of the mass is:
Answer:
Explanation:
Coin slide across the floor and finally comes to stop with an increase in temperature.
We can conclude that the coin interacted with one or more object which reduces its velocity.
- It is also possible that coin stop due to friction which elevates the coin temperature by converting some part of its energy into thermal energy