Which of the following statements are true? (mark all that apply)
1 answer:
Answer:
(a) and (b)
Explanation:
Energy is the capacity to do work, and exists in various forms. These forms can be converted one to another by the use of appropriate means. Some examples are sound, mechanical, solar, light, which causes the sensation of vision, etc. energy is measured in Joules (J).
The rate of transfer of energy is called power.
i.e Power =
It is measured in Watts (W).
When a white light is disperses into its colors, gray and black are not part of the colors. And a black sometimes could be as a result of the absorption of all other colors of light.
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Answer:
given,
speed of the car = 20 m/s
final speed of car = 0 m/s
distance between car and the deer = 38 m
reaction time, t = 0.5 s
deceleration of the car = 10 m/s².
a) distance between deer and car
distance travel in the reaction time
d₁ = v x t
d₁ = 20 x 0.5 = 10 m
distance travel after you apply brake
using equation of motion
v² = u² + 2 a s
0 = 20² - 2 x 10 x s
s = 20 m
total distance traveled by the car
D = d₁ + d₂
D = 20 + 10 = 30 m
distance between car and the deer = 38 m - 30 m
= 8 m
b) now, maximum speed car.
distance travel in reaction time
d₁ = s x t
d₁ = 0.5 V
distance left between them
d₂ = 38 - d₁
d₂ = 38 - 0.5 V
distance travel after you apply brake
using equation of motion
v² = u² + 2 a d₂
0 = (V)² - 2 x 10 x (38 - 0.5 V)
V² + 10 V - 760 = 0
now, solving the quadratic equation
V = 23.01 , -33.01
rejecting the negative term.
hence, maximum speed of the car could be V = 23.01 m/s