Exothermic because exothermic reactions transfer energy to the surroundings. Endothermic reactions take in energy from the surroundings, so if you want to warms people's hands you should use exothermic chemical reaction for the product.
Answer:
U = - 4 x 
Explanation:
ΔV = potential difference =
Volts
q = charge on electron =
C
electric potential energy is given as
U = q ΔV = (
) (
)
= - 4 x 
To solve this problem we will apply the concept related to the amplitude and the Doppler effect. The difference between the maximum and minimum frequency detected by the microphone would be given by the mathematical function

Here,
= Source Frequency
= Speed of microphone
v = Speed sound

Maximum speed of the microphone is



Now the amplitude is

Here T means the Period, then

A= 0.2605m
Therefore the amplitude of the simple harmonic motion is 0.2605m
Answer:
Explanation:
We shall apply law of conservation of momentum to know the Speed of northward moving vehicle before collision to check the veracity of driver's statement .
Let v be the velocity of composite mass after collision
Applying law of conservation of momentum in north direction
m v₂ = 2m v sin55.08
Applying law of conservation of momentum in east direction
m x 13 = 2m v cos55.08
Dividing these two equations
v₂ / 13 = tan55.08
v₂ = 13 tan55.08
= 18.62 m/s
= (18.62 x60 x 60) / 1000
= 67 km/h
= 67 x 5/8 mi/h
= 42 mi/h
So he is lieing.