Thecorrect answer is B.
hope this helps brainliest would be cool if not its fine
Answer:
Speed of the ball relative to the boys: 25 km/h
Speed of the ball relative to a stationary observer: 35 km/h
Explanation:
The RV is travelling at a velocity of

Here we have taken the direction of motion of the RV as positive direction.
The boy sitting near the driver throws the ball back with speed of 25 km/h, so the velocity of the ball in the reference frame of the RV is

with negative sign since it is travelling in the opposite direction relative to the RV. Therefore, this is the velocity measured by every observer in the reference frame of the RV: so the speed measured by the boys is
v = 25 km/h
Instead, a stationary observer outside the RV measures a velocity of the ball given by the algebraic sum of the two velocities:
v = +60 km/h + (-25 km/h) = +35 km/h
So, he/she measures a speed of 35 km/h.
Frequency = speed / wavelength
(6 m/s) / (12 m) = 0.5 Hz.
That's not infrared light.
Infrared light waves move about 50 million times faster than that, and they're only about 0.00000007 as long as that.
Answer:Water Only
Explanation:
Given
vessel is insulated therefore no heat can be added or removed i.e. heat exchange is zero
If hot water at
is mixed with cold water at
then at equilibrium vessel contains only water and final temperature of water will be between
and 
Heat released by hot water is equal to heat gain by cold water .
Answer:
248
Explanation:
L = Inductance of the slinky = 130 μH = 130 x 10⁻⁶ H
= length of the slinky = 3 m
N = number of turns in the slinky
r = radius of slinky = 4 cm = 0.04 m
Area of slinky is given as
A = πr²
A = (3.14) (0.04)²
A = 0.005024 m²
Inductance is given as


N = 248