<span>A van is traveling on a road at a speed of 55 km/h relative to a
stationary observer on the side of the road. A girl sitting near the
driver of the van throws a paper airplane to a boy at the back of the
van with a speed of 2 km/h relative to the girl, the boy, and the van.
The speed of the paper airplane, relative to the same stationary observer
on the side of the road, is (55 - 2) = 53 km/h. No rounding is necessary.</span>
Answer: 65.25 J
Explanation:
Kinetic Energy K.E. = 1/2 * m * v^2 ; where m is the mass of the body and v is the velocity of the body ; K.E. = 1/2 * 0.145 * 30 * 30 = 65.25 Joules
That is force. Whenever you see the words push or pull always think of Force
Answer: Tension = 47.8N, Δx = 11.5×
m.
Tension = 95.6N, Δx = 15.4×
m
Explanation: A speed of wave on a string under a tension force can be calculated as:

is tension force (N)
μ is linear density (kg/m)
Determining velocity:


0.0935 m/s
The displacement a pulse traveled in 1.23ms:


Δx = 11.5×
With tension of 47.8N, a pulse will travel Δx = 11.5×
m.
Doubling Tension:



|v| = 0.1252 m/s
Displacement for same time:


15.4×
With doubled tension, it travels
15.4×
m
Answer:9.34 A/s
Explanation:
Given
radius of solenoid 
Emf induced 
no of turns per meter n=450
we know Induced EMF is given by

Magnetic Field is given by

thus 
Area of cross-section
where
solving integration we get

where r=distance from axis
R=radius of Solenoid


