In physics, "work<span>" is when a force applied to an object moves the object in the same direction as the force. If someone pushes against a wall, no </span>work<span> is done on the system. It is calculated as follows:
Work = Force x distance
Work = 25 N x 4 meters
Work = 100 N.m</span>
Answer:17.08 s
Explanation:
Given
distance between First and second Runner is 45.6 m
speed of first runner
=3.1 m/s
speed of second runner
=4.65 m/s
Distance between first runner and finish line is 250 m
Second runner need to run a distance of 250+45.6=295.6 m
Time required by second runner 
time required by first runner to reach finish line
Thus second runner reach the finish line 80.64-63.56=17.08 s earlier
Answer:
Explanation:
Impulse of reaction force of floor = change in momentum
Velocity of impact = √ 2gh₁
= √ 2 x 9.8 x 1.5 = 5.4 m /s.
velocity of rebound = √2gh₂
= √ 2x 9.8 x 1
= 4.427 m / s.
Initial momentum = .050 x 5.4 = .27 kg m/s
Final momentum = .05 x 4.427 = .22 kg.m/s
change in momentum = .27 - .22 = .05 kg m/s
Impulse = .05 kg m /s
Impulse = force x time
force = impulse / time
.05 / .015 = 3.33 N.
kinetic energy = 1/2 m v²
Initial kinetic energy = 1/2 x .05 x 5.4²
= 0.729 J
Final Kinetic Energy =1/2 x .05 x 4.427²
= 0.489 J
Change in Kinetic energy =0 .24 J
Lost kinetic energy is due to conversion of energy into sound light etc.
Answer:
1 Ampere.
Explanation:
From the question given above, the following data were obtained:
Resistor 1 (R₁) = 20 ohm
Resistor (R₂) = 20 ohm
Voltage (V) = 10 V
Current (I) =?
Next, we shall determine the equivalent resistance in the circuit. This can be obtained as follow:
Resistor 1 (R₁) = 20 ohm
Resistor (R₂) = 20 ohm
Equivalent Resistance (R) =?
Since the resistors are in parallel connection, the equivalent resistance can be obtained as follow:
R = (R₁ × R₂) / (R₁ + R₂)
R = (20 × 20) / (20 + 20)
R = 400 / 40
R = 10 ohm
Finally, we shall determine the total current in the circuit. This can be obtained as illustrated below:
Voltage (V) = 10 V
Equivalent Resistance (R) = 10 ohm
Current (I) =?
V = IR
10 = I × 10
Divide both side by 10
I = 10 / 10
I = 1 Ampere
Therefore, the total current in the circuit is 1 Ampere.
