百度试题 结果1 题目 A ball is thrown upwards and its height, h metres, above ground after seconds is given by h=1+4t-5t^2.Write an expression for the velocity of the ball at time t. 相关知识点: 试题来源: 解析 v=4-10t 反馈 收藏 ...
2. A ball is thrown vertically upwards. The upward direction is considered the positive direction Assuming that air resistance is negligible, which of the following statements is correct?C A When the ball is at the highest point, its acceleration is zero B Its velocity is negative during the ...
1.A ball is thrown directly upwardswith an initial velocity of 20m/s.Determine the ball’s maximum height and thetime it will take for the ball to fall from its maximum height to the ground.(10 marks)2.A man hauls a 20kg stone thatis currently resti
2. A ball is thrown vertically upwards with speed u m s-' from a point P at height h metres above the ground. The ball hits the ground 0.75 s later. The speed of the ball immediately before it hits the ground is 6.45 m s'. The ball is modelled as a particle.(a)Show that u=...
Using (4) with a =-g=-1020= 40t-0.5×10xwhere t seconds is the time passed since the ball was thrown up.5- 40t+20=0-8t+4=0Using the quadratic formulat==7.62 or 0.54The ball is 20 m above the point of release twice, at t = 0.54 s(on way up) and t= 7.62 s (on way ...
A. it reaches a certain height and stops B. the force of gravity acts on it C. there is no more force acting on it D. it changes direction on its own 相关知识点: 试题来源: 解析 B。原因:当球被抛向空中时,它会一直向上运动,直到重力作用在它上面并把它拉下来。反馈...
A ball is thrown upwards so that its height (h) at the end of t seconds is h=160t - 16t^2 ft. FInd the maximum height? A ball is thrown into the air with an upward velocity of 28 ft/s. Its height (h) in feet ...
A ball is thrown straight up into the air. Its height above the ground over time is best represented by which graph? A. A straight line going up. B. A parabola opening upwards and then downwards. C. A horizontal line. D. A curve that continuously goes up. 相关知识点: ...
8 A small ball is thrown vertically upwards with speed 12ms', from a point 5 m above the ground.Assuming air resistance is negligible, find(i) the greatest height above the ground reached by the ball,[2] (ii) the time taken for the ball to reach the ground.[3] ...
A-level物理试题02