Answer:
Thermal energy always flows from the warmer object to the colder object. This causes your hand to get cold, while the ice absorbs your heat and melts.
Answer:
The number of people at game are approximately 22909
Explanation:
Given data
When one person shout
When n number of person shout together
The sound intensity level during one person shout is given by:
The sound intensity level during n number of person shout is given by:
Since each person generates same sound intensity and hence total number of persons can be determined as
Hence
The number of people at game are approximately 22909
Answer:
I = 1.06886 N s
Explanation:
The expression for momentum is
I = F t = Δp
therefore the momentum is a vector quantity, for which we define a reference system parallel to the floor
Let's find the components of the initial velocity
sin 28.2 = v_y / v
cos 28.2= vₓ / v
v_y = v sin 282
vₓ = v cos 28.2
v_y = 42.8 sin 28.2 = 20.225 m / s
vₓ = 42.8 cos 28.2 = 37.72 m / s
since the ball is heading to the ground, the vertical velocity is negative and the horizontal velocity is positive, it can also be calculated by making
θ = -28.2
v_y = -20.55 m / s
v_x = 37.72 m / s
X axis
Iₓ = Δpₓ =
since the ball moves in the x-axis without changing the velocity, the change in moment must be zero
Δpₓ = m - m v₀ₓ = 0
v_{fx} = v₀ₓ
therefore
Iₓ = 0
Y axis
I_y = Δp_y = p_{fy} -p_{oy}
when the ball reaches the floor its vertical speed is downwards and when it leaves the floor its speed has the same modulus but the direction is upwards
v_{fy} = - v_{oy}
Δp_y = 2 m v_{oy}
Δp_y = 2 0.0260 (20.55)
= 1.0686 N s
the total impulse is
I = Iₓ i ^ + I_y j ^
I = 1.06886 j^ N s
Answer:
The bystander will hear a frequency of 931.18 Hz.
Explanation:
let V = 39.5 m/s be velocity of the police car and Fs be the frequency a siren of the police car emits. let v = 0 m/s be the velocity of the bystander and Vs = 340 m/s is the velocity of sound in air.
then, we know that the bystander has to hear a higher frequency than the one emitted and the frequency that the bystander hears is given by the doppler relation:
Fo = [(Vs)/(Vs - V)]×Fs
= [(Vs)/(Vs - V)]×Fs
= [(340)/(340 - 39.5)]×(823)
= 931.18 Hz
Therefore, the bystander will hear a frequency of 931.18 Hz.