4. 1 and 2 only.
1. the downward force is the force of gravity.
<span>2. The upward force exerted is the Normal reaction from the floor.</span>
Answer:
v = 54.2 m / s
Explanation:
Let's use energy conservation for this problem.
Starting point Higher
Em₀ = U = m g h
Final point. Lower
= K = ½ m v²
Em₀ = Em_{f}
m g h = ½ m v²
v² = 2gh
v = √ 2gh
Let's calculate
v = √ (2 9.8 150)
v = 54.2 m / s
Answer:
v = 10 m/s
Explanation:
given,
Mass of Mercedes engine = 2000 Kg
Power delivered = 100 kW
angle made with horizontal = 30°
acceleration due to gravity = 10 m/s²
largest speed car can sustain = ?
we know,
Power = Force x velocity
P = F x v
P = mg sinθ x v
P = mg sin 30° x v
P = 0.5 mg x v

v = 10 m/s
hence, the maximum velocity is equal to v = 10 m/s
Answer:
1.7N
Explanation:
Force = kx
Where x = spring compression and
K = spring constant
K =85N/m
x = 2.0cm / 100
= 0.02m
Force = 85 x 0.02
= 1.7N
Reflection: a change in direction of a wave at a boundary between two different media.
sentence: i saw my reflection in the mirror.
refraction: the bending of light as it passes from one transparent substance into another.
sentence: when light goes through glass, it’s a refraction.
diffraction: the bending of waves around the corners of an obstacle.
sentence: spaced tracks on a CD act as a diffraction.
absorption: the process or action by which one thing absorbs or is absorbed by another.
sentence: heat waves hitting the beach usually give most of their energy to the sand.
interference: when two waves lay on each other and their energies are either added together or cancelled out.
sentence: interference waves can be observed with all types of waves.
standing wave: two waves moving in opposite directions. they both have the same amplitude or frequency.
sentence: plucking the string of a guitar is an example of standing waves.
resonance: increased amplitude that occurs when the frequency of a force is equal or close to a natural frequency.
sentence:a buzz in your car that only occurs at a certain speed is an example or resonance.