A particle is thrown with the speed u at an angle $\mathrm{\alpha }$ with the horizontal. When the particle makes an angle $\mathrm{\beta }$ with the horizontal, its speed will be:

• A

  u cos $\mathrm{\alpha }$

• B

  u cos $\mathrm{\alpha }$ sec $\mathrm{\beta }$

• C

  u cos $\mathrm{\alpha }$ cos $\mathrm{\beta }$

• D

  u sec $\mathrm{\alpha }$ sec $\mathrm{\beta }$