Top answers

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
4653 Views

How do B-Lymphocytes Work?

B-Lymphocytes remain in the bone marrow until they mature and then spread throughout the body, concentrating in the lymph nodes and the spleen.They express a specific intrinsic protein called a B-cell recept...
MJ
Answered by Michael J. • Biology tutor
10363 Views

How to write a History Essay?

There’s no simple way to write a history essay. Even those who have been in the field for years are not always perfect. However, there are some tips that always apply. 1. Structure- Always make sure your ess...
MJ
Answered by Michael J. • History tutor
3986 Views

How do I structure a History Essay?

How to Structure a History Essay Structuring a history essay can be a daunting task – but once you establish a clear technique for presenting your argument, the clarity and quality of your essays will undoub...
OO
Answered by Oliver O. • History tutor
17711 Views

Explain the theory of a 'separation of powers'

Montesquieu first popularised the theory, saying 'power shall check power'; meaning that each branch of the state (the Legislative, the Executive and the Judicary) should have equal power to oversee and over...
RP
Answered by Robert P. • Politics tutor
2753 Views