Answer:
Vf = 3.67 [m/s]
Explanation:
To solve this problem we must use the following equation of kinematics.
where:
Vf = final velocity [m/s]
Vi = initial velocity = 4.3 [m/s]
a = acceleration or desacceleration = 0.5 [m/s²]
x = distance = 5 [m]
Note: The negative sign in the above equation means that the velocity of the ball is decreasing (desacceleration).
Now replacing:
Vf² = (4.3)² - (2*0.5*5)
Vf² = 18.49 - 5
Vf² = 13.49
using the square root, we have.
Vf = 3.67 [m/s]
Answer:
(b) 32.2°
Explanation:
Using Snell's law as:
Where,
is the angle of incidence ( 30.0° )
is the angle of refraction ( ? )
is the refractive index of the refraction medium (Material B, n=5 / 4)
is the refractive index of the incidence medium (Material A, n=4 / 3)
Hence,
Angle of refraction = 
= 32.2°
Deceleration isn't a term in physics; you can have positive acceleration which is speeding up and negative acceleration which is slowing down
Use newton's law F = ma
a = F/m
Answer:
e. All of these statements are false.
Explanation:
As we know that heat transfer take place from high temperature to low temperature.
It is possible to convert all work into heat but it is not possible to convert all heat in to work some heat will be reject to the surrounding.
The first law of thermodynamics is the energy conservation law.
Second law of thermodynamics states that it is impossible to construct a device which convert all energy into work without rejecting the heat to the surrounding.
By using heat pump ,heat can transfer from cooler body to the hotter body.
Therefore all the answer is False.
Answer:
The runner's acceleration as she sped up to the finish line is 0.95m/s²
Explanation:
Acceleration is the change in velocity of a body with respect to time. It is expressed as;
Acceleration = change in velocity/time
Change in velocity = final velocity - initial velocity
Acceleration = final velocity - initial velocity / time
Given initial speed = 8.0m/s
Final speed = 9.9m/s
Time taken = 2.0s
Acceleration = 9.9-8.0 / 2.0
Acceleration = 1.9/2
Acceleration = 0.95m/s²
