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A ball of mass 0.7 kg strikes the wall at an angle of 90 degrees with speed 72 km/h. Consider that the bounce lasts for 0.1 s and is perfectly elastic. What is the magnitude of the average reaction force from the wall that acts on the ball?

initial speed: v = 72 km/h = 20 m/s. mass: m = 0.7 kg time of the impact: t = 0.1 s average force: F The speed after impact is the same as initial speed, but velocity has got the opposite direction. Therefor...
FM
Answered by Filip M. • Physics tutor
4679 Views

What is the difference between speed and velocity?

Speed and velocity may seem like identical measures but this is not the case. Speed is a scalar measurement meaning it only takes into account magnitude not direction, velocity is a vector quantity and there...
AA
Answered by Alexander A. • Physics tutor
9743 Views

Resolving the forces for an object suspended on two strings.

Imagine a following situation: a stationary (not moving) object with a mass of 5 kg is suspended in the air by two strings. The angles between strings and the vertical directions are 15 and 55 degrees. What ...
FW
Answered by Filip W. • Physics tutor
20285 Views

What is the difference between a scalar and a vector? Give 3 examples of each.

A scalar is a quantity that has only magnitude (size) E.G Distance, Speed, Temperature A vector is a quantity that has magnitude and a direction. E.G Displacement, Velocity, Change in Temperature.
MK
Answered by Marcin K. • Physics tutor
4084 Views

An electron falling from one energy level to another emits a photon of wavelength 550nm. What is the difference between the two energy levels?

The key equation is that of the energy of a photon. E = hc/ λ​ Using λ​ = 550nm gives E = 3.61x10^-19J (Remember that a nanometer is 1x10^-9 m ). Using the conservation of energy, the energy of this photon m...
JL
Answered by Jamie L. • Physics tutor
3863 Views