Answer:
(A) 7.9 m/s^{2}
(B) 19 m/s
(C) 91 m
Explanation:
initial velocity (U) = 0 mph = 0 m/s
final velocity (V) = 85 mph = 85 x 0.447 = 38 m/s
initial time (ti) = 0 s
final time (t) = 4.8 s
(A) acceleration = 
= 
= 7.9 m/s^{2}
(B) average velocity = 
=
= 19 m/s
(C) distance travelled (S) = ut + 
= (0 x 4.8) + 
= 91 m
Answer: (A) Gravitational force are proportional to the masses of the two objects.
Explanation:
Answer:
v_f = 30 m/s
Explanation:
v_f = v_I + a*t
v_f = 0m/s + (9.81m/s²)*(3s)
v_f = 29.43m/s
v_f = 30 m/s
Since the object is being launched horizontally off the cliff the only vertical force acting on the ball is gravity which is an acceleration of 9.81m/s². So we have all the flowing information to use the the kinematic equation: v_f = v_I + a*t.
Answer:
Mechanical waves
Explanation:
Waves are periodic oscillations, that carry energy, but not matter.
Waves are classified into two types:
- Mechanical waves: these waves are produced by the oscillations of the particles in a medium, which can oscillate along the direction of propagation of the wave (longitudinal wave) or perpendicular to the direction of motion of the wave (transverse wave). These waves can only propagate in a medium, so they cannot travel in a vacuum. Examples of mechanical waves are sound waves.
- Electromagnetic waves: these waves are produced by the oscillations of electric and magnetic field. They are transverse waves. They are the only type of wave able to propagate through a vacuum (so, through space).
Therefore, the waves that need molecules in order to transfer energy are mechanical waves.
Answer:
Explanation:
Given that,
Hot reservoir temperature is
TH = 58°C
TH = 58 + 273 = 331 K
Cold reservoir temperature
TC = -17°C
TC = -17°C + 273 = 256K
In 24minutes 590 J of heat was removed from hot reservoir
t = 24mins
t = 24 × 60 = 1440 seconds
Then,
Power is given as
P = E / t
P = 590 / 1440
P = 0.41 W
Since this removed from the hot reservoir, then, QH = 0.41W
We want to find heat expelled to the cold reservoir QX
Efficiency is given as
η = 1 - TH/TC = 1 - QH/QC
1 - TH/TC = 1 - QH/QC
TH/TC = QH/QC
Make QC subject of formula
QC = QH × TC / TH
QC = 0.41 × 256 / 331
QC = 0.317 W
