Answer:
a
Explanation:
<u>In order to maintain speed, a moving object or person must move at a constant velocity</u>. Accelerating will increase the speed while decelerating will reduce the speed.
Hence, for Bolt to be able to maintain the top speed for a few seconds, he needs to move at a constant velocity.
The correct option is a.
Answer:
a= -0.86 m/s²
The negative sign shows that ball down the ground or moving down
Explanation:
Vf² - Vo² = 2gS
where
Vf = velocity of clay as it hits the ground
Vo = initial velocity of clay = 0
g = acceleration due to gravity = 9.8 m/sec^2 (constant)
S = distance travelled by clay = 15 m
Substituting appropriate values,
Vf² - 0 = 2(9.8)(15)
Vf = 17.15 m/sec.
Formula to use is,
V - Vf = aT
where
V = velocity of clay when it stops = 0
Vf = 17.15 m/sec (as determined above)
a = acceleration
T = 20 ms
Put the values to find acceleration
a=(V-Vf)/T
a=(0-17.15)/20
a= -0.86 m/s²
The negative sign shows that ball down the ground
Answer:
a) I₁ = 11.2 Lux
, vertical direction
, b) I₂ = 1.44 Lux
Explanation:
a) A polarized is a system that absorbs light that is not polarized in the direction of its axis, therefore half of the non-polarized light must be absorbed
consequently the above the processed light has half of the incident intensity and the directional of the polarized
I₁ = I₀ / 2
I₁ = 22.4 / 2
I₁ = 11.2 Lux
is polarized in the vertical direction
b) The polarized light falls on a second polarizer, therefore it must comply with the law of Malus
I₂ = I₁ cos² θ
I₂ = 11.2 cos² 69
I₂ = 1.44 Lux
Answer: D(t)= 50(4/5)^t
Explanation: If 1/5 of the temperature difference is lost each minute, that means 4/5 of the difference remains each minute. So each minute, the temperature difference is multiplied by a factor of 4/5 (or 0.8).
If we start with the initial temperature difference, 50° Celsius, and keep multiplying by 4/5, this function gives us the temperature difference t minutes after the cake was put in the cooler.
Answer:
250 J
Explanation:
Apply the formula:
K = 1/2.m.v²
K = 1/2.5.10²
K = 1/2.5.100
K = 5.50
K = 250 Joules
But, remember that if the speed is accelerating or not, if it is, then we need to know the point in time that the question is asking for the Kinetic Energy.
In this case, I think it is just a constant speed.
