Answer:
90J
Explanation:
The only time work is being done is when he lifts the box off the ground. Therefore, using the work formula, 2 x 45, you get 90J. Hope this helps someone.
Answer:
The amplitude of the spring is 32.6 cm.
Explanation:
It is given that,
Mass of the block, m = 2 kg
Force constant of the spring, k = 300 N/m
At t = 0, the velocity of the block, v = -4 m/s
Displacement of the block, x = 0.2 mm = 0.0002 m
We need to find the amplitude of the spring. We know that the velocity in terms of amplitude and the angular velocity is given by :
So, 
A = 0.326 m
or
A = 32.6 cm
So, the amplitude of the spring is 32.6 cm. Hence, this is the required solution.
Answer: The passage of a light wave can cause electrically charged particles to move up and down.
Explanation:
Electromagnetic waves are transversal waves, they are a combination of oscillating electric and magnetic fields, which propagate through space carrying energy from one place to another.
This means the oscillation of the wave occurs in the transversal direction to its propagation. In addition, electromagnetic waves are spread thanks to the electromagnetic fields produced by moving electric charges.
Answer:
car B will be 30 Km ahead of car A.
Explanation:
We'll begin by calculating the distance travelled by each car. This is illustrated below:
For car A:
Speed = 40 km/h
Time = 3 hours
Distance =?
Speed = distance / time
40 = distance / 3
Cross multiply
Distance = 40 × 3
Distance = 120 Km
For car B:
Speed = 50 km/h
Time = 3 hours
Distance =?
Speed = distance / time
50 = distance / 3
Cross multiply
Distance = 50 × 3
Distance = 150 Km
Finally, we shall determine the distance between car B an car A. This can be obtained as follow:
Distance travelled by car B (D₆) = 150 Km
Distance travelled by car A (Dₐ) = 120 Km
Distance apart =?
Distance apart = D₆ – Dₐ
Distance apart = 150 – 120
Distance apart = 30 Km
Therefore, car B will be 30 Km ahead of car A.
